When acetic acid and $K_4[Fe(CN)_6]$ are added to a copper salt,a chocolate precipitate is obtained of the compound:

State the importance of coordination compounds in:
$1$. Industrial processes
$2$. Biological systems

Assign $A, B, C, D$ from the given type of reaction.
$2K_3[Fe(CN)_6] + 3FeCl_2 \longrightarrow Fe_3[Fe(CN)_6]_2 \downarrow + 6KCl$

Assign $A, B, C, D$ from the given type of reaction.
$K_4[Fe(CN)_6] + 2CuSO_4 \longrightarrow Cu_2[Fe(CN)_6] \downarrow + 2K_2SO_4$

$CO$ (Carbon monoxide) is a neutral oxide of carbon,but it acts as a very strong field ligand and associates with metals to form complex compounds. These complex compounds are very useful in metallurgical processes. $CO$ is a poisonous gas because:

Identify the complexes formed in the following processes:
$I$. Mond's process for purification of nickel
$II$. Removal of unreacted $AgBr$ from photographic plates
$III$. Removal of lead poisoning from the body